化简求值x/(x+y)+y/(x-y)-2xy/(x^2-y^2),其中x=5,y=2
化简求值:x-y/x²-2xy+y²-xy+y²/x²-y²,其中(x
化简求值:根号x^-2xy+y^2 + x^2 -6xy+9y^2/x-3y,其中x=根号3,y=根号5
化简求值:(x+y)(x-y)+(x-y)²-(6x²y-2xy²)÷2y,其中x=-2,
先化简再求值(x-y)(x+y)-(x-2y) 的完全平方+x(3x-5y)-(x-y)(x-2y),其中x=1/2 y
先化简,再求值(x-y/x+y)^2÷(y-x/x^2+2xy+y^2)^2*1/x+y,其中x=-4,y=1
化简求值(x+2y)^2-(2x+y)(2x-y)-5y(y-x) 其中 x=1/3 y= -1/2
化简求值:(x-y)^2-(2x+y)(2x-y)-2(2x^2+xy),其中x=-1,y=4分之1
①化简求值:2(x^2y+xy)-3(x^2y-xy)-4x^2y,其中x=1,y=-1.
化简求值3x[xy-2x(y-2x)]+3y(x²-y²),其中x=-1,y=2
化简求值:2(x的平方y+xy)-3(x平方y+xy)-4x平方y,其中x=-1,y=2
化简求值{(x=2y)(5x-2y)-(3x+2y)(3x-2y)]/4x,其中x=2,y=-1
化简求值:[(x+y)(x-y)-(x-y)²+2y(x-y)]÷4y,其中x=二分之一,y=2